A subject-matter of the present invention is compounds of general formula (I) 
in which
X represents a hydrogen or halogen atom,
Y represents one or more atoms or groups chosen from hydrogen, halogens and methyl, methoxy and nitro groups, R1 represents a (C1-C4) alkyl group, R2 and R3 each represent, independently of one another, a hydrogen atom or a (C1-C4) alkyl group or else R2 and R3 form, with the nitrogen atom which carries them, a pyrrolidinyl, piperidinyl or morpholinyl group.
The preferred compounds are those in the general formula of which X represents a halogen atom, Y represents a hydrogen atom or a halogen atom, R1 represents a methyl group, R2 represents a hydrogen atom or a methyl group and R3 represents a methyl group or else R2 and R3 form, with the nitrogen atom which carries them, a pyrrolidinyl ring.
The compounds of general formula (I) can be prepared by processes illustrated by the following scheme: 
According to this scheme, a compound of general formula (II), in which X is as defined above and Rxe2x80x2 represents a C1-C4) alkyl group, is subjected to an alkylation reaction with a halide of general formula HalR1, in which R1 is as defined above, to result in a compound of general formula (III). This compound is subsequently reacted with a chlorooxoacetate of general formula ClCOCO2Rxe2x80x3, in which Rxe2x80x3 represents a (C1-C4) alkyl group, in a polar aprotic solvent, such as dichloroethane, at room temperature, in the presence of a Lewis acid, for example titanium tetrachloride, in order to obtain the diester of general formula (IV). The latter is subsequently treated in acetic acid, first at room temperature and then at the reflux temperature, with a phenylhydrazine optionally substituted by a Y group as defined above, in order to obtain an ester of general formula (V). Finally, this ester is converted to the secondary or tertiary amide of general formula (I) by the action of an amine of general formula HNR2R3, in which R2 and R3 are as defined above, for example in the presence of a trialkylaluminium derivative in a solvent such as toluene.
The starting compounds of general formula (II) are known to a person skilled in the art. By way of indication, mention will be made of the formation of 6-chloroindole-2-carboxylic acid derivatives according to Rydon et al., J. Chem. Soc (1955), 3499.
The examples which will follow illustrate the preparation of some compounds according to the invention. The elemental microanalyses and the I.R. and N.M.R. spectra confirm the structures of the compounds obtained.
The numbers shown between brackets in the titles of the examples correspond to those in the 1st column of the table given later.
In the names of the compounds, the dash xe2x80x9c-xe2x80x9d forms part of the word and the dash xe2x80x9c-xe2x80x9d is only used for the break at the line end; it is to be omitted in the absence of a break and must not be replaced either by a normal dash or by a space.